266 Black Currant Eelworm 



continued apparently without cessation for a period of from 7 — 10 days, 

 after which time death ensued. The number of worms kept under 

 observation for this experiment was roughly 1400, and of these only 

 29 returned to the highly motile state described. 21 of these proved 

 to be larval forms, 5 were females and the remainder were of undeter- 

 mined sex. The limited number of worms surviving this experiment 

 prevented any microscopic examination of them being undertaken, 

 otherwise comparative results between these and the worms about to 

 be described would be interesting. External examination of these 

 worms after death for this purpose was not successful and the unex- 

 pectedly large amount of material used in this experiment left nothing 

 for further experimental work on the subject. 



The type of activity described above presented a sharp contrast 

 to that exhibited by other worms in the colonies examined. This took 

 place after the movements due to expansion of tissues had ceased and 

 consisted of slow occasional movements during which the body was 

 swayed slowly from side to side and drawn upward, while one half, 

 usually the posterior, remained in a stationary position. Several 

 minutes would elapse before such movements were repeated. The 

 worms exhibiting this type of movement, which was shewn by approxi- 

 mately 30 per cent., never became actively motile, nor did they remain 

 in a state of activity for so long a period as the worms previously 

 described. The worms which shewed neither type of movement among 

 the colonies consisted of (i) dead, and (ii) broken specimens, both of 

 which occurred in much the same proportions. 



An examination of the worms which had remained in a state of 

 desiccation for the 6 months' period shewed that in this case the two 

 types of movement were not distinguishable and that approximately 

 70 per cent, of the worms returned to an actively progressive state 

 after a comparatively short immersion period of from 1 — 2 hours. 



The results obtained from those which had undergone the same 

 process for the 6 weeks' period shewed that fully 80 per cent, of the 

 worms returned to the normally active state after the short immersion 

 period of from \ to 1| hours. 



It must be noted here that in many of the colonies examined there 

 was strong evidence of parasitism to which the presence of numerous 

 broken bodies of worm must be attributed. Predatory acarids are 

 numerous on the black currant and it is possible that they are partly 

 responsible for the considerable mortality which occurs among the 

 worms in their quiescent condition. 



